A new international trial has shown that pair of cancer drugs can shrink tumours in nearly 60% of people with advanced melanoma, which is the most serious form of skin cancer.

The trial which was conducted on 945 patients found that treatment with ipilimumab and nivolumab stopped the cancer from advancing for nearly a year in 58% of cases.

BBC reports that it also showed that taking both drugs led to tumours shrinking by at least a third in 58% of patients who had the tumours stable or shrinking for an average of 11.5 months.

According to the Cancer Research United Kingdom who presented the data at the American Society of Clinical Oncology, the drugs deliver a "powerful punch" against one of the most aggressive forms of cancer.

The figures, published simultaneously in the New England Journal of Medicine, for ipilimumab on its own were 19% and 2.5 months.

Explaining the treatment, Dr James Larkin, a consultant at the Royal Marsden Hospital and one of the UK's lead investigators said:

"By giving these drugs together you are effectively taking two brakes off the immune system rather than one so the immune system is able to recognise tumours it wasn't previously recognising and react to that and destroy them. For immunotherapies, we've never seen tumour shrinkage rates over 50% so that's very significant to see. This is a treatment modality that I think is going to have a big future for the treatment of cancer."

However, there was the issue of side-effects such as fatigue, a rash or diarrhoea which were unresolved, moreso as more than half of those tested had side effects on combination therapy compared to around a quarter on ipilimumab alone.

In addition, it is uncertain why some people responded exceptionally well to treatment, while others had no benefit at all.

Ipilimumab is a drug given intravenously every 3 months and costs around £100,000 (over N30 million) for a year while Nivolumab is given every 2 weeks until it stops working.